Around 200 refugees managed to break into the port of Calais in northern France on Saturday (Jan 23) after a demonstration of support for migrants living in a slum nearby ended, enabling some of them to board the front deck of a British ferry, an official said.

Migrants run away from tear gas thrown by police forces near the Channel Tunnel in Calais, ahead of attempts to raze the camp on Thursday. Photo: AP

"A demonstration in Calais has drawn around 2,000 people and in the end around 200 people entered the port, with approximately 50 of them boarding a ferry, the 'Spirit of Britain', on an external deck," deputy Calais prefect Denis Gaudin said.

MS Spirit of Britain is a cross-channel ferry operated by P&O Ferries. Gaudin said that some of the refugees had decided to quit the boat voluntarily and that the rest would be removed by police, if necessary by force.

Migrants managed to break through the Port of Calais’ defences and reached the deck of the P&O Ferry Spirit of Britain Image: Louis Witter

A spokeswoman for P&O Ferries said the port of Calais was still closed on Saturday (Jan 23) evening. She said the migrants had not managed to get inside the ship, as staff had locked the doors to prevent all access from the deck.

Thousands of refugees fleeing war and poverty in Africa and the Middle East have gathered over the past year in a vast slum near Calais, dubbed "the jungle", using it as a stopover point before trying to smuggle their way across to Britain in the hope of a better life.